Umarex Umarex Zelos picatinny rail out of tolerance?

I just attempted to mount an existing scope / picatinny mount that I have on my new Zelos. The mount will not mate correctly with the slots on the top of the rifle mount. It seems as though the rifle picatinny slots are not cut deep enough to allow the mounting screws to pass through.

This is a cheap picatinny scope mount that I have, labeled as "M223". Oddly, it fits my AR upper just fine.

Can anyone recommend a brand of picatinny scope mounts that will work with the zelos?

Tnx!

Frank
 
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I just attempted to mount an existing scope / picatinny mount that I have on my new Zelos. The mount will not mate correctly with the slots on the top of the rifle mount. It seems as though the rifle picatinny slots are not cut deep enough to allow the mounting screws to pass through.

This is a cheap picatinny scope mount that I have, labeled as "M223". Oddly, it fits my AR upper just fine.

Can anyone recommend a brand of picatinny scope mounts that will work with the zelos?

Tnx!

Frank
Weaver, picatinny, nato. All look the same and almost are but in the end are dimensionally different.
 
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Weaver, picatinny, nato. All look the same and almost are but in the end are dimensionally different.
This is the mount I am using. Midway calls it out as a Picatinny mount. I need to check to see if Zelos uses a Picatinny term for the top scope mount as well.

This does not fit the Zelos.

 
I just attempted to mount an existing scope / picatinny mount that I have on my new Zelos. The mount will not mate correctly with the slots on the top of the rifle mount. It seems as though the rifle picatinny slots are not cut deep enough to allow the mounting screws to pass through.

This is a cheap picatinny scope mount that I have, labeled as "M223". Oddly, it fits my AR upper just fine.

Can anyone recommend a brand of picatinny scope mounts that will work with the zelos?

Tnx!

Frank

It's your mount, the Zelos pic is in spec.
 
OK... this is what I found. I think the "edge break" of the zelos mount violates the Picatinny spec. Reference : https://www.biggerhammer.net/picatinny/1913_specs.pdf

It appears that the Zelos radius of the apex of the outer angular sections of the mount is quite a bit "fatter/softer" than my Picatinny rails on my AR uppers. So that edge is not as sharp and the edge break is too "soft / rounded" (if that makes sense). The slot depth does not extend far enough down to align with the vertex points on the edge of the Umarex mount. So what is going on is that the scope mount is being pulled down onto the mount and the recoil lugs are experiencing interference with the bottom of the slots on the zelos mount. In other words, I need the slots on the zelos rail mount a little bit deeper.

picatinny1.jpg


Below is a picture of my zelos. See how the edge of the rail is rounded bit? If you note, the slot itself is raised up just a little above the edge of the vertex rail. BTW, the zelos rail is likely fully "cast" and not machined. Take a close look, and you can see that there is sort of a light-gray line under the slot which kinda hints at the roundness. That slot is also just a tiny bit raised above the vertex point of the outer angle. It should bottom out closer to the center of the vertex, and the vertex should be sharp. Run your finger on this edge, and it feels very soft.

zelos.jpg


Here's a rail on one of my AR uppers in the image below. The rail's vertex edge on my machined AR uppers are significantly more "sharp", even though the images that I captured don't represent that well. The bottom of the slot is closer, although still slightly offset, to being coincident with the vertex.

AR.jpg


That bit of thicker edge break of the cast rail of the Zelos causes the interference fit with the the Nikon scope base recoil lug screws. If you have a two piece clamp for your picatinny accessories, one that has the tightening screws well above the slots, you are likely good to go. If you have a mount that uses recoil lug screws that depend on tight tolerances at the bottom of those rail slots, your mount may not work. Or if you have a recoil lug screw mount that is designed for out of spec rails tolerances (which would be the smart thing to do if you were designing accessories), you are likewise good to go.

I've got to put about a half inch riser on this gun anyway in order to get the ergonomics to work better, as the Nikon mount that I have is too low. The Zelos itself has very little or no drop to the stock, and the cheek piece is too high such that I have to cant my head to look through the scope. I'm hoping that if I get a picatinny interposer to lift it up, that the interposer will have loose enough tolerances to fit bot rifle and scope mount. Otherwise I will need to pull those rail(s) and touch up those slots a little on my mill.

Bottom line is that the scope mount depends on the rail meeting the mil std spec. The Nikon mount is unforgiving in tolerance, and this is likely why this mount is no longer in production. Coupling that unforgiving Nikon mount to the sloppy tolerance of the Umarex rail, and it is a no-go.

Ugh. I just want to shoot this thing already :)
 
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OK... this is what I found. I think the "edge break" of the zelos mount violates the Picatinny spec. Reference : https://www.biggerhammer.net/picatinny/1913_specs.pdf

It appears that the Zelos radius of the apex of the outer angular sections of the mount is quite a bit "fatter/softer" than my Picatinny rails on my AR uppers. So that edge is not as sharp and the edge break is too "soft / rounded" (if that makes sense). The slot depth does not extend far enough down to align with the vertex points on the edge of the Umarex mount. So what is going on is that the scope mount is being pulled down onto the mount and the recoil lugs are experiencing interference with the bottom of the slots on the zelos mount. In other words, I need the slots on the zelos rail mount a little bit deeper.

View attachment 524201

Below is a picture of my zelos. See how the edge of the rail is rounded bit? If you note, the slot itself is raised up just a little above the edge of the vertex rail. BTW, the zelos rail is likely fully "cast" and not machined. Take a close look, and you can see that there is sort of a light-gray line under the slot which kinda hints at the roundness. That slot is also just a tiny bit raised above the vertex point of the outer angle. It should bottom out closer to the center of the vertex, and the vertex should be sharp. Run your finger on this edge, and it feels very soft.

View attachment 524202

Here's a rail on one of my AR uppers in the image below. The rail's vertex edge on my machined AR uppers are significantly more "sharp", even though the images that I captured don't represent that well. The bottom of the slot is closer, although still slightly offset, to being coincident with the vertex.

View attachment 524208

That bit of thicker edge break of the cast rail of the Zelos causes the interference fit with the the Nikon scope base recoil lug screws. If you have a two piece clamp for your picatinny accessories, one that has the tightening screws well above the slots, you are likely good to go. If you have a mount that uses recoil lug screws that depend on tight tolerances at the bottom of those rail slots, your mount may not work. Or if you have a recoil lug screw mount that is designed for out of spec rails tolerances (which would be the smart thing to do if you were designing accessories), you are likewise good to go.

I've got to put about a half inch riser on this gun anyway in order to get the ergonomics to work better, as the Nikon mount that I have is too low. The Zelos itself has very little or no drop to the stock, and the cheek piece is too high such that I have to cant my head to look through the scope. I'm hoping that if I get a picatinny interposer to lift it up, that the interposer will have loose enough tolerances to fit bot rifle and scope mount. Otherwise I will need to pull those rail(s) and touch up those slots a little on my mill.

Bottom line is that the scope mount depends on the rail meeting the mil std spec. The Nikon mount is unforgiving in tolerance, and this is likely why this mount is no longer in production. Coupling that unforgiving Nikon mount to the sloppy tolerance of the Umarex rail, and it is a no-go.

Ugh. I just want to shoot this thing already :)
I'm impatient enough to chuck up the offending bolts in a drill and flap wheel them down mill out the slots a little more because let's be honest I'm probably leaving these optics forever or swapping out the fasteners.

You understood the mission! This is the happiest an agn post has ever made me.

07-19-26-my-strange-fascination-with-football-when-did-predator-v0-9bhwjte9bjod1.jpeg
 
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I'm impatient enough to chuck up the offending bolts in a drill and flap wheel them down mill out the slots a little more because let's be honest I'm probably leaving these optics forever or swapping out the fasteners.

You understood the mission! This is the happiest an agn post has ever made me.

View attachment 524241
That pics just reminded me... where the hell has @Dairyboy been?
 
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I'm impatient enough to chuck up the offending bolts in a drill and flap wheel them down mill out the slots a little more because let's be honest I'm probably leaving these optics forever or swapping out the fasteners.
I also thought about just swapping them out for longer, small diameter screws and fastening the screws with nylock nuts... but that image in my mind makes me cringe. I'll wait to get the picatinny riser in hand to figure out what approach to take.
 
I also thought about just swapping them out for longer, small diameter screws and fastening the screws with nylock nuts... but that image in my mind makes me cringe. I'll wait to get the picatinny riser in hand to figure out what approach to take.
If you have a power drill or drill press, and a file or angle grinder you can bs a reduced shank bolt. Or a mini lathe, but you'd be done already.
 
it’s always the mounts. I’ve had this happen ….get different mounts
Well, this scope mount fits every other rail I've got, from throw away $300 Palmetto uppers to a $1600 compass lake upper. Cheapest way to do this is to just wait to see if the riser I've got on the way will work as an interposer for both the Zelos and the Nikon. If not, I've got a mill and a sharpie. The worst thing would be an unfinished aluminum surface under the scope mount. The factory finish on this gun already leaves a lot to be desired. I'll know tomorrow what I have to do.. Fingers crossed! (With a little luck, I will have inaugural rounds down range by nightfall tomorrow.)
 
OK... I found a fix. I bought a UTG picatinny riser that clamps onto the Zelos rail, and which accepts the Nikon mount just fine. The height of the scope now fits my my eye much better, but holy cow... the center of axis for the scope is cartoonishly above the center of axis for the rifle barrel. I guess this is likely the price I pay for a bullpup! I will need to have a very good dope sheet for range variation.

Let the fun commence!
 
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OK... I found a fix. I bought a UTG picatinny riser that clamps onto the Zelos rail, and which accepts the Nikon mount just fine. The height of the scope now fits my my eye much better, but holy cow... the center of axis for the scope is cartoonishly above the center of axis for the rifle barrel. I guess this is likely the price I pay for a bullpup! I will need to have a very good dope sheet for range variation.

Let the fun commence!
If it makes you feel better mine are 3.75 in above bore axis and tilted 25 degrees on one gun and 30 degrees on the other. Being as low as possible used to be important to me before I learned of tilted bases and dialing, and comfort, but nobody could shoot my guns unless they were built like me. I'm glad you found a workaround.
 
I just attempted to mount an existing scope / picatinny mount that I have on my new Zelos. The mount will not mate correctly with the slots on the top of the rifle mount. It seems as though the rifle picatinny slots are not cut deep enough to allow the mounting screws to pass through.

This is a cheap picatinny scope mount that I have, labeled as "M223". Oddly, it fits my AR upper just fine.

Can anyone recommend a brand of picatinny scope mounts that will work with the zelos?

Tnx!

Frank
Hmmm...

Like this barra is ?

 
Hmmm...

Like this barra is ?

Ha! Not quite that bad :)
 
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